The invention relates to an automatic regulator for breathing apparatus, comprising a chamber which communicates with the breathing apparatus, including therein an air-dispensing valve, an a chamber which communicates with the environment, said chambers being sealingly separated from each other by means of a flexible membrane which controls the dispensing valve, while the chamber which communicates with the environment is defined exteriorly by a cover provided with pressure means acting on said membrane, for manual control of the dispensing valve.
With an automatic regulator for breathing apparatus of this type, the air output is caused by each inhaling action, due to the inward deflection of the separating membrane, within the chamber communicating with the breathing apparatus, due to the vacuum produced by said inhaling action.
In order to effect an air output in the absence of an inhaling action, said separating membrane may be depressed inwardly of the chamber which communicates with the breathing apparatus, thanks to manually-controlled means provided in the cover which defines exteriorly said chamber which communicates with the environment. Said means generally comprises a pushbutton which is axially slidably mounted in the cover and which is held in its rest condition, i.e. at a certain distance from the membrane, by means of a spring. In this instance, by depressing said pushbutton, said membrane is pushed inwardly of the chamber which communicates with the breathing apparatus, and it causes a manual opening of the dispensing valve.